The ‘Mommy Brain’ Is Bigger: How Love Grows a New Mother’s Brain

Take heart, new moms: you may be feeling overwhelmed, exhausted and distracted, but your brain is actually growing. Especially if you’re the kind of mom who’s been driving your friends and family mad by talking about how perfect, special and beautiful your new child is.

Despite the fact that the term “mommy brain” typically describes mindless behavior — like putting the milk away in the closet and your hat in the fridge — a new study published in Behavioral Neuroscience finds that women’s brains may actually get bigger during new motherhood. The study’s authors took brain scans of 19 moms two to four weeks after birth and again two to four months later, and found that their brains showed growth in midbrain regions involved with the experience of pleasure and in the prefrontal cortex, which is linked to reasoning, planning and judgment. (More on Time.com: See photos of the Grosse Pointe Moms Club)

New mothers who seemed to take more pleasure and joy in their role as parent — selecting from a list of adjectives more positive words like “ideal” to describe their infants, and words such as “proud” and “blessed” to describe their experience of parenthood — saw greater growth in their emotion-processing regions.

“This is a nice study,” says Dr. Bruce Perry, a child psychiatrist and senior fellow of the Child Trauma Academy, who was not involved with the research (full disclosure: Perry and I have written two books together). “It is exactly what you would expect knowing what we do about how neural systems respond to patterns of activation. The [parallel] parts in the [baby’s] brain…would be much more likely to be getting repetitive stimulation from the somatosensory input from the loving mother — and I would predict [these kinds of] changes in the mother’s brain as well. Love can change the brain.”

The study looked only at brain size, not changes in the mothers’ cognition, but the author notes that the two typically go hand-in-hand. “There’s certainly reason to think it might indicate that they got smarter,” says lead author Pilyoung Kim, who worked on the study as a graduate student at the Yale Child Study Center and is now at the National Institute on Mental Health. “It could be [smarter] particularly in the parenting context or more generally. We don’t know.” (More on Time.com: Building a Brighter Kid: Consider IVF)

Kim has a 4-month-old baby herself and says, “‘It’s very emotionally intense. I don’t see my own brain, but I can see that change is definitely a possibility based on the intensity of the experience.”

While any type of learning or experience must produce lasting changes in the brain in order to be remembered, these changes do not usually include the brain’s pleasure or reward regions. One of the few experiences that does alter these areas, however, is addiction. “You might say we’re addicted to motherhood,” laughs Elizabeth Meyer, co-author of an accompanying commentary on the new research. “Activation of the reward system releases endorphins [hormones that bind to the brain’s opiate receptors and reduce pain], which may help us forget things like labor pain, how tired you might be during the first few months, morning sickness.”

Meyer, who has a 3-year-old and is also halfway through a new pregnancy, adds, “Being a mom and also being pregnant right now, it’s all very rewarding. If we had to learn from punishing factors, I don’t think we’d do it over and over. If you focused only on morning sickness and pain — no one would do it again. The rewards have to outweigh the punishments.” (More on TIME.com:Mompetition: Why You Just Can’t Make Mom Friends)

Indeed, the brain systems involved in addiction probably evolved to compel people and animals to perform certain behaviors in spite of their negative consequences — that tendency can be very useful for some situations, particularly parenting. “Your emotions are a huge factor in what you do every day,” explains Meyer. “They’re navigational aids for every decision we make. If mothers are happy, several things are happening. One is that the reward centers have increased activity and their memory is going to be better. They will associate happy things with the experience of their infant and any way you can reinforce these pathways in the brain is going to relate to stronger behavior, in this case stronger maternal behavior.”

The current research could not determine what made the happier mothers so happy: whether, for example, they had easier babies or a genetic predisposition toward better moods. Or, perhaps, whether they had been primed in their own childhood to become more attentive mothers later on. In previous research, Kim found that mothers who had had more nurturing from their own mothers during childhood had larger brain volumes in areas related to reading faces and empathy, and that these mothers showed more activation in these regions in response to infant cries. Animal research finds the same thing: childhood experience seems to be an important factor in determining later parenting behavior. (More on TIME.com:How Not to Raise a Bully)

Data show also that women who suffer from postpartum depression are less able to tend to their children. Their inability to take pleasure from parenthood makes it harder for them to nurture their babies, especially in the face of all the difficulties that come with new motherhood, including lack of sleep and exhaustion. These early experiences can have a negative effect on children’s development; here, basically lack of “addiction” to the baby might be the problem.

Fortunately, for women who are having difficulty with the transition to parenthood, there’s no need to beat yourselves up for feeling overwhelmed or depressed. Your best option is to seek professional help, which can help greatly. And, says Perry, if mothers “act as if” they feel happy, it not only may help prevent depressed maternal mood from affecting children, but it can also help feelings of real pleasure kick in for the parent.

“If they actually mimic the somatosensory behaviors that would normally be part of an energized, loving mother — hold, rock, smile, talk — that will both help their child and help them become less depressed. It is likely to be useful to the developing infants brain to get ‘approximate’ somatosensory experience, even if the poor depressed mother doesn’t feel it yet. It is a reciprocal interaction. The baby can actually help heal the mother as she helps the baby develop,” says Perry. (More on Time.com: 5 Pregnancy Taboos Explained (or Debunked)).